Study of the Abundance Patterns in the Metal-Poor Stellar Stream
Study of the Abundance Patterns in the Metal-Poor Stellar Stream
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DOI：
10.1017/pasa.2012.015
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发表时间：
2012-09
影响因子：
6.3
通讯作者：
Hong-jie Li;Shuai Liang;W. Cui;Bo Zhang
中科院分区：
文献类型：
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作者：
Hong-jie Li;Shuai Liang;W. Cui;Bo Zhang
恒星流中贫金属恒星的化学丰度为建立中子俘获过程模型提供了重要信息。对这些恒星的研究可以让我们更好地了解早期银河系的r过程核合成和化学组成。利用更新的主r过程和弱r过程模式，我们拟合了恒星流恒星的丰度。样本恒星的弱r过程成分系数几乎是恒定的，包括富r恒星，这意味着弱r过程和铁都是II型超新星产生的主要元素，它们的产量几乎是恒定的质量分数。流星和富r星之间的区别是显而易见的。对于流星来说，随着金属丰度的增加，主要r过程成分系数呈增加趋势，这意味着相对于铁，主要r过程元素的产量逐渐增加。这种行为表明，主r过程的祖先质量小于弱r过程的祖先质量。此外，我们还发现贫金属流星HD 237846是一颗弱r过程星。
Abstract The chemical abundances of the metal-poor stars in the stellar stream provide important information for setting constraints on models of neutron-capture processes. The study of these stars could gives us a better understanding of the r-process nucleosynthesis and chemical composition of the early Galaxy. Using the updated main r-process and weak r-process patterns, we fit abundances in the stellar stream stars. The weak r-process component coefficients are almost constant for the sample stars, including r-rich stars, which means that both the weak r-process and Fe are produced as primary elements from Type II supernovae and their yields have nearly a constant mass fraction. The difference between the stream stars and r-rich stars is obvious. For the stream stars, the fact that the increased trend in the main r-process component coefficients as metallicity increases means a gradual increase in the production of main r-process elements relative to iron. This behaviour implies that the masses of progenitors for the main r-process are smaller than those of the weak r-process. Furthermore, we find that the metal-poor stream star HD 237846 is a weak r-process star.